1. Field of the Invention
The present invention relates to an image forming apparatus such as a copying machine and a printer, which has a function to form an image on a recording material such as a sheet.
2. Description of the Related Art
As disclosed in Japanese Patent Application Laid-Open No. 2006-98772, in general, in an image forming apparatus such as an LED type printer and an LED type copying machine, an LED light beam corresponding to image data generated based on a print object is radiated to a photosensitive member so as to form an electrostatic latent image on the photosensitive member. Toner is supplied from a cartridge (process cartridge) to the electrostatic latent image on the photosensitive member so as to form a toner image on the photosensitive member. The toner image is transferred onto a recording material, and then fixed thereto. In this way, an image is formed on the recording material.
In this image forming apparatus, an LED unit for radiating the LED light beam needs to be arranged near the photosensitive member so as to face the photosensitive member. Thus, in an LED type monochromatic/color image forming apparatus, LED units corresponding to respective colors are set between the cartridges.
Therefore, in this apparatus, the cartridges cannot be replaced by being forward drawn out from the apparatus.
Japanese Patent Application Laid-Open No. 2008-275805 discloses a structure in which the LED units are retracted above the cartridges along with an opening operation of an upper door so that the cartridges are forward drawn out from a main body of the image forming apparatus.
However, in the structure of Japanese Patent Application Laid-Open No. 2008-275805, the upper door (support member) on which the LED units (exposure devices) are mounted may be closed even when the cartridges and a receiving tray for holding the cartridges in a removable manner are being moved in front and rear directions of the main body of the image forming apparatus.
Therefore, in this structure, the upper door may be closed even under a state in which the cartridges are out of image forming positions, and hence the LED units may be damaged.